It takes two to get one in trouble. – Grenade homes in and sticks to the target's face. After sticking to an enemy, it deals damage over time until the target dies or the grenade detonates. Upon exploding, it sends out life orbs that heal allies.
Usage & Description
Instead of releasing child grenades upon detonation, the Kiss of Death seeks out and sticks to the target's face dealing constant elemental DoT for the length of the fuse time (always 3 seconds), including explosive damage. This makes the Kiss of Death less effective than the standard counterpart for dealing with several targets but instead deals massive damage to a single enemy.
The child grenade count reflects the number of life orbs released and the Kiss of Death has increased damage when compared to standard transfusion grenades of a similar level.
Before patch 1.0.7, the chest containing Kiss of Death (Moxxi's Toy Box) could have been reopened after it disappears in the main story. It was respawning when the Vault Hunter entered Concordia from Triton Flats, either using Moxxi's Back Door past the slot machines in Moxxi's bar, or the main door by the Black Market, or from The Meriff's Office. This bug allowed Vault Hunters to obtain multiple copies of the Vibra-Pulse, Slammer, and Kiss of Death.
This grenade mod's special damage over time can score multiple critical hits if the grenade sticks to the face of an enemy.
The Kiss of Death refers to a kiss given to one who has committed an act of betrayal and is marked for death.
Borderlands 2 - Grenade Mods - Kiss of Death (Transfusion)